# CVE-2026-58101 — JONASBN Crypt::OpenSSL::X509

> As of 2026-07-14, CVE-2026-58101 is a HIGH-severity vulnerability in JONASBN Crypt::OpenSSL::X509, CVSS v3.1 7.5, EPSS 0.1% (1.3th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-58101 as of 2026-07-14; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-07-14

## What is CVE-2026-58101?

Crypt::OpenSSL::X509 versions before 2.1.3 for Perl allow denial of service via NULL pointer dereference. X509V3_EXT_d2i(ext) returns NULL when an extension's DER value fails to parse. basicC, ia5string, and auth_att dereference its result without a NULL check. keyid_data also dereferences akid->keyid, which is NULL for an empty AKI SEQUENCE (DER 30 00) even when the parse succeeds. A caller invoking an affected helper on an extension from an untrusted certificate triggers a SIGSEGV that crashes the Perl process.

The record classifies CVE-2026-58101 under weakness class [CWE-476](https://intel.threadlinqs.com/cwe/CWE-476). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 84 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.5 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **EPSS (FIRST):** 0.1% probability of exploitation in the next 30 days, higher than 1.3% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 3.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-13, last modified 2026-07-14

## Is CVE-2026-58101 being exploited?

It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.

## Affected products and versions

- **JONASBN**: Crypt::OpenSSL::X509

## How to fix CVE-2026-58101

No vendor patch reference has been recorded for CVE-2026-58101 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-58101

No threat campaign in the Threadlinqs corpus currently references CVE-2026-58101, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-07-15. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [github.com — patch](https://github.com/dsully/perl-crypt-openssl-x509/commit/4c1e2370556097c253ae27abe9e1097ea377fbd2.patch)
- [metacpan.org — release notes](https://metacpan.org/release/JONASBN/Crypt-OpenSSL-X509-2.1.3/source/Changes.md)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-58101
Full detection coverage and IOCs for threats exploiting CVE-2026-58101 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp